Porsche has revived one of its most recognizable racing-inspired designs with the one-off Flachbau RS, an extreme reinterpretation of the 911 GT2 RS that draws heavily from the legendary 935 “Moby Dick.” Built for a single customer, the project extensively reengineers a 2018 991.2 GT2 RS with a focus on weight reduction, retro styling and modern aerodynamic performance.
The original Porsche 935 was created in 1976 from the Type 930 911 Turbo, with the 935/75 version earning the Moby Dick nickname because of its dramatic aerodynamic bodywork. Porsche later brought the design influence to the road with the Flachbau, or Slant Nose, 911 Turbo, while enthusiasts and independent builders including Singer, Rezvani Retro and Gunther Werks have produced their own interpretations.
Porsche itself recreated the concept in 2018 with a limited run of 77 cars. In 2026, however, the German automaker has taken the idea considerably further with a single production Flachbau RS.
Porsche Flachbau RS Was Built Around One Customer’s Vision
The project began with a like-new 2018 Porsche 911 GT2 RS equipped with the optional Weissach Package. The commissioning owner wanted the car to be as focused on performance as possible and specifically requested the removal of comfort features that added weight.
Over nearly three years, specialists and engineers from across Porsche worked on the project, including Manthey Racing. The Porsche Communication Management infotainment system was removed along with the sound system, sound-deadening materials and floor coverings.
The wiring harness was also redesigned, with obsolete wiring removed and the remaining system protected by simple sheathing. The cabin retains its red Alcantara and black leather theme with carbon-fiber accents, but the result is intentionally raw and stripped back.
The extensive weight-saving measures reduce the car’s weight by nearly 70 pounds, bringing it to roughly 3,100 pounds including fluids. Even items such as the warning triangle and towing eye were moved into a removable box, allowing the owner to remove additional weight before track driving without compromising the car’s road-legal status.
Retro Flachbau Styling Meets Modern Porsche Engineering
Grant Larson, the designer behind Porsche’s 935 reinterpretation created for the 935’s 70th anniversary, returned from retirement to help design the Flachbau RS.
The car is finished in a specially developed Grand Prix White paint, complemented by matte-black accents and exposed carbon fiber inspired by the Martini Racing appearance of the 935/78.
The front fenders are positioned lower than those of the GT2 RS, requiring modifications to the fuel filler cap and its mechanism. Instead of traditional pop-up headlights, the Flachbau RS uses three separate LED elements for high beams, low beams and daytime running lights.
Each headlight unit measures just under 1.5 inches, while the daytime running lights are less than 0.78 inches. With the lights illuminated, the design initially recalls the Porsche 718 Cayman range, but closer inspection reveals the stronger visual connection to the 935.
Aerodiscs on the wheels reinforce the vintage motorsport character while adding another contemporary interpretation of the classic racing design.
Three-Stage Rear Wing Delivers Massive Downforce
The Flachbau RS also receives a new three-stage rear wing mounted on patented, adjustable S-shaped supports. Porsche says the system generates even more downforce than a Manthey-tuned GT2 RS.
At 211 mph, the rear axle produces roughly 1,221 pounds of downforce. Achieving that figure required extensive computational fluid dynamics development before production tooling was created, followed by extensive real-world testing.
The Flachbau RS was evaluated using three test vehicles, including more than 50 laps of the Nürburgring Nordschleife. Porsche test driver Lars Kern contributed to the development, while total testing covered approximately 93,200 miles.
A GT2 RS Focused on Performance Rather Than Luxury
The Flachbau RS stands apart from many modern one-off supercars by emphasizing engineering and driving performance rather than additional luxury. Its owner specifically chose to remove features instead of adding them, creating a road-legal car designed around the fundamentals of lightweight performance.
The underlying GT2 RS retains its 691-horsepower 3.8-liter twin-turbo flat-six, meaning the project did not require more power to become more extreme.
Instead, Porsche focused on reducing weight, reshaping the bodywork and developing its aerodynamic performance while preserving the road-legal character of the original car.
The result is a modern interpretation of the Flachbau concept that combines the raw character of Porsche’s early RS models with contemporary engineering. Limited to a single production example, the Flachbau RS also demonstrates how far Porsche’s Sonderwunsch program can go when a customer prioritizes track performance over luxury and exclusivity for its own sake.
